Excavation survey and outcrop observation of fault appearing along the Wakayama River associated with the 2024 Noto Peninsula Earthquake

Yasue, Kenichi*; Hiramatsu, Yoshihiro*; Ogawa, Satoshi*; Yamazaki, Reiji*; Hirose, Kentaro*; Miura, Kazumasa*; Shirahama, Yoshiki*; Sugito, Nobuhiko*; Mukoyoshi, Hideki*; Fujita, Natsuko   ; Nagata, Hidehisa*; Tateishi, Ryo*; Doke, Ryosuke*; Ogura, Takuro*; Utsugi, Koichi*

In the Noto Peninsula earthquake in 2024, fault scarps exceeding 2 m were formed in some areas along the Wakayama River. Part of this scarps overlap with existing cliff. This suggests that the fault may have been displace in the past. In this study, we carried out the excavation survey across the fault scarp to clarify the mechanism of scarp formation and past displacement. In addition, heavy rains on the Noto Peninsula in September 2024 caused large-scale flooding in the Wakayama River. The fault outcrop appeared due to lateral erosion caused by floodwaters. We also observed this outcrop.